What is the maximum support spacing for flexible ducting in horizontal runs?

The maximum support spacing for flexible ducting in horizontal runs is 4 feet. This requirement is critical for ensuring that the duct maintains its shape and does not sag, which could obstruct airflow and reduce system efficiency. Proper support helps to prevent physical stress on the duct material, which might lead to tears or leaks over time. Additionally, maintaining the specified support spacing contributes to the overall integrity of the HVAC system, ensuring it operates efficiently and effectively throughout its lifespan. This guideline is commonly referenced in industry standards and codes, emphasizing the importance of proper installation practices in HVAC systems.